Improve appearance of text-shadow when dark navbar colors are used; adjust color of carets in navbar menus according to the navbar color
Define brand image in CSS instead of an <img> tag to allow it to be styled; add high resolution tentacle brand image for retina/high-res displays; create non-clashing light version of tentacle brand image to be used when darker custom colors are chosen in settings
Add black color setting
Merge pull request #145 from daprice/master

Improve nav bar appearance when custom colors are used